Measuring Arrangement And Method For A Thermal Analysis Of A Sample

ABSTRACT

A measuring arrangement and method for a thermal analysis of a sample, having a crucible for storing a sample in the crucible, as well as a sensor for measuring a sample temperature of the sample when the crucible is arranged on the sensor. To provide for a high level of reproducibility of measurements in the case of such a measuring arrangement and a method for the thermal analysis performed with the measuring arrangement, the measuring arrangement has an anti-rotation protection for the crucible, in order to provide a predetermined rotational position of the crucible with respect to the sensor when the crucible is arranged on the sensor. The invention includes a method for the thermal analysis of a sample, which is performed using such a measuring arrangement.

TECHNICAL FIELD mon The present invention relates to a measuringarrangement and method for a thermal analysis of a sample. BACKGROUND

Such measuring arrangements and methods for the thermal analysis of asample realized therewith are known from in various designs the priorart.

The methods, which are of interest here, have in common that at leastone sample arranged in a sample chamber is temperature-controlledaccording to a temperature program, in the course of which a chambertemperature in the interior of the sample chamber is changed, wherein atleast one sample temperature of the sample is measured in the course ofthe temperature program by means of a sensor, which is assigned to therespective sample.

The measuring arrangement, which can be used in the case of such amethod for arranging the sample and for measuring the sample temperatureand which is to be arranged in the sample chamber for this purpose, hasa crucible for storing a sample in the crucible and a sensor formeasuring a sample temperature of the sample when the crucible isarranged on the sensor.

In the case of many methods of the thermal analysis, two such measuringarrangements are required in the respective sample chamber, for examplefor simultaneously temperature-controlling the “actual sample (to beanalyzed)” as well as a further sample, typically referred to as“reference” or “reference sample”, according to the temperature programin the same sample chamber in the case of the method.

As alternative for such an arrangement of a reference sample in thecrucible of the second measuring arrangement, it can also be consideredto operate the crucible of the second measuring arrangement “empty”(i.e., without a sample or reference sample, respectively, locatedtherein) in the case of such a method.

Examples for such methods for the thermal analysis involving twomeasuring arrangements of the mentioned type are, e.g., the differentialthermal analysis (DTA) as well as, e.g., the method of the so-calleddifferential scanning calorimetry (DSC) derived therefrom. Besides thementioned sensor for measuring the sample temperature, or each measuringarrangement, respectively, can also have further means for measuring oneor a plurality of physical variables in the course of the temperatureprogram. Corresponding methods are often combined under the termsimultaneous thermal analysis (STA). An example for this is thedetermination of the temperature-dependent calorific effects of a sampleby means of DSC with simultaneous determination of thetemperature-dependent mass of the sample by means of thermogravimetry(TG).

In the case of many known measuring arrangements and methods for thethermal analysis realized therewith, there is no arrangement position,which is specified in a defined manner, of the crucible on the sensor,viewed in the lateral direction in the case of the measuringarrangement. In fact, a user can arrange the crucible within certainlimits at any location on the sensor prior to performing a thermalanalysis. In many applications, it then follows that the reproducibilityof corresponding measuring processes of the thermal analysis is impactedin response to repeated removal and new re-arrangement of the crucibleon the sensor, for instance in response to performing a series ofmeasurements.

To increase the reproducibility of the measurements performed as part ofthe thermal analysis, a “centering” of a crucible on the sensor wasrealized according to an internal prior art from the applicant in thecase of a measuring arrangement of the above-mentioned type, in that atop side of the sensor was embodied with a sensor edge protrudingupwards in such a way that the crucible is thereby centered in itsarrangement on the sensor by means of positive connection (crucible ofcircular contour in a matching receiving chamber, which is defined bythe sensor edge). According to this improved embodiment, the location,at which a user can arrange the crucible on the sensor, is thus fixedlypredetermined in an advantageous manner.

In practice, however, it turned out that the reproducibility is notalways satisfactory even with an embodiment of the measuringarrangement, which is improved in this way, in some applications, forinstance in the case of a series of measurements, which are to beperformed with high demands on the measuring accuracy.

SUMMARY

It is an object of the present invention to provide for a high level ofreproducibility of measurements in the case of a measuring arrangementand a method for the thermal analysis of the above-mentioned typeperformed with said measuring arrangement.

To solve this object, the measuring arrangement is characterized by ananti-rotation protection for the crucible according to a first aspect ofthe invention, in order to provide a predetermined rotational positionof the crucible with respect to the sensor when the crucible is arrangedon the sensor.

An improved reproducibility can be attained in a simple way by means ofthe invention in an advantageous manner, in particular, e.g., also inthe case of rotationally symmetrically configured crucibles. In the caseof crucibles, which are configured in a rotationally symmetrical manner,deviations from the rotational symmetry, which are caused by productiontolerances and which impact the reproducibility of measurements, areobviously responsible for this, as long as a user can arrange thecrucible in any or random rotational position, respectively, withrespect to the sensor, as in the prior art. In particularly preferredembodiment, the anti-rotation protection according to the invention forthe crucible is provided in combination with a centering of the cruciblewith respect to the sensor.

A “crucible” in terms of the invention consists of or comprises a basebody, hereinafter also referred to as crucible body, which has at leastapproximately the shape of a shell or of a cup. With regard to thesituation of use, in the case of which the crucible is arranged on thesensor, the crucible body has a section, which will be referred to as“bottom” hereinafter, which represents a lower end section of thecrucible body facing the sensor (in the situation of use), as well as asection, which will be referred to as “jacket” hereinafter, whichrepresents a lateral limitation of the crucible body and which extendsin the direction away from the sensor (upwards), starting from thebottom. The bottom and the jacket of the crucible limit an interior ofthe crucible, in which the sample may be located, stored on the bottom.The crucible can (optionally) be provided with a cover, which closes(completely or partially) an opening of the crucible, which is otherwiselocated at the top end of the jacket. Such a cover can be embodied,e.g., as separate part and can be attached (detachably ornon-detachably) at a top edge of the jacket. In particular crucibles,e.g., the crucible body of which has an at least approximatelycylindrical or frustoconical shape, can be used in the context of theinvention. The crucible can have, e.g., a maximum lateral expansion inthe range of between 3 and 15 mm and/or a height in the range of between2 and 10 mm, preferably in a lateral expansion/height ratio in the rangeof between 1.0 and 1.5. A wall thickness of the crucible body can be,e.g., in the range of between 50 and 300 μm.

It can be provided as part of the invention that the measuringarrangement further has an “outer crucible” for storing the crucible inthe outer crucible, wherein the crucible is made of a crucible materialand the outer crucible is made of an outer crucible material, whichdiffers from the crucible material.

An “outer crucible” in terms of this further development of theinvention consists of or comprises a base body, also referred to as“outer crucible body” hereinbelow, which has at least approximately theshape of a shell or of a cup, wherein with regard to the intended use(storage of the crucible), the outer crucible body has at least onesection, which can be referred to as (outer crucible) “jacket”, whichrepresents a lateral limitation of the outer crucible body, and whichcan optionally have a section, which is to be referred to as (outercrucible) “bottom”, which represents a lower end section of the outercrucible body facing the sensor (in the situation of use) and which isconnected on the bottom side of the jacket. An interior of the outercrucible, which is limited by the jacket (and the bottom, which may bepresent), on the inner side of the jacket, is to be dimensioned in sucha way thereby that the crucible of the measuring arrangement can bestored therein.

In a preferred embodiment of the outer crucible, the latter has acircular contour, viewed in top view. In the context of the invention,in particular outer crucibles can be used, e.g., the outer crucible bodyof which has an at least approximately cylindrical or frustoconicalshape. The outer crucible can have, e.g., a maximum lateral expansion inthe range of between 3 and 15 mm and/or a height in the range of between2 and 5 mm, preferably in a lateral expansion/height ratio in the rangeof between 1 and 10. A wall thickness of an outer crucible jacket and/ora wall thickness of an outer crucible bottom can in particular be, e.g.,in a range of between 50 and 250 μm.

The use of an outer crucible makes it possible in an advantageous mannerto avoid a direct contact between the crucible and the sensor, so that areaction between crucible and sensor material is avoided. This is so,because unwanted chemical reactions and/or physical reactions (e.g.,diffusion or welding processes) can otherwise occur between samplematerial and crucible material, as well as between crucible and sensormaterial, in particular when relatively high temperatures occur in theinterior of the sample chamber or relatively high sample temperaturesresulting therefrom, respectively, in the course of the temperatureprogram. The outer crucible storing the crucible can be made of amaterial, which is particularly well compatible with the respectivecrucible material as well as particularly well compatible with therespective sensor material. Advantageously, the crucible and the outercrucible are embodied in such a way and the crucible is stored in theouter crucible in such a way that in the situation of use, the crucibleonly contacts an inner side of the outer crucible, and the sensor onlycontacts an outer side of the outer crucible.

With regard to the situation of use, the “sensor” comprises a top side,above which the crucible can be stored. As will be described below, thistop side can be embodied to be even or uneven and can in particular bemade of a metallic material, e.g., at least on the surface. To be ableto measure the sample temperature of a sample located in the crucible bymeans of the sensor, the sensor can in particular have, e.g., below thementioned surface, e.g., a thermoelement or other means, which aresuitable for the temperature measurement. In a special embodiment, thesensor consists of at least two different materials, in particularmetallic materials, which are arranged in such a way that athermoelement for the measurement of the sample temperature is alreadyembodied therewith. In particular a sensor, e.g., which has an at leastapproximately circular disk-shaped shape, can be used in the context ofthe invention. The sensor can have, e.g., a maximum lateral expansion inthe range of 1.0-times to 1.5-times the maximum lateral expansion of thecrucible.

It is provided in one embodiment of the invention that the crucible hasa marking, which is visible for a user, in the area of its outer side,in order to make it possible for the user to arrange the crucible on thesensor in the predetermined rotational position of the crucible withrespect to the sensor by means of the marking.

This embodiment makes it possible for the user to always arrange thecrucible in the same rotational position with respect to the sensor onthe sensor, in that the crucible is thereby rotated in such a way thatthe mentioned marking is in the predetermined position (rotationalposition).

A visible marking can advantageously furthermore also be provided in thearea of the sensor or on a component of the measuring arrangement, whichis arranged in a stationary manner to the sensor, for instance to beable to bring the two markings “into alignment” with regard to the angleof rotation in response to arranging the crucible on the sensor.

It is provided in a further development of this embodiment that themarking is embodied as a marking protrusion or as a marking depression,wherein the marking protrusion or the marking depression, respectively,preferably has a configuration, which is elongated in the verticaldirection of the crucible and/or a width in the range of between 0.1 mmand 1.0 mm, viewed in a circumferential direction of the crucible.

If a visible marking is additionally also provided in the area of thesensor or on a component of the measuring arrangement, which is arrangedin a stationary manner to the sensor, this visible marking can also beembodied as a marking protrusion or as a marking depression, preferablycomprising a configuration, which is elongated in the vertical directionof the measuring arrangement and/or a width in the range of between 0.1mm and 1.0 mm, viewed in a circumferential direction of the sensor.

It is provided in one embodiment that when the crucible is arranged onthe sensor, the predetermined rotational position of the crucible withrespect to the sensor is ensured by means of a positive engagement of aprotrusion with a depression, wherein the protrusion is arranged on thesensor or on a further component of the measuring arrangement, which isarranged in a stationary manner to the sensor, and the depression isarranged in the area of the outer side of the crucible, or vice versa.

It is provided in a first alternative of this embodiment that thedepression arranged in the area of the outer side of the crucible or theprotrusion arranged in the area of the outer side of the crucible,respectively, are arranged directly on the outer side of a jacket of thecrucible.

In a second alternative of this embodiment, the measuring arrangementfurther has a component, which surrounds the crucible at least in thearea of a jacket of the crucible, in particular an outer cruciblestoring the crucible, wherein the depression arranged in the area of theouter side of the crucible or the protrusion arranged in the area of theouter side of the crucible, respectively, is arranged on the outer sideof this component surrounding the crucible, in particular outercrucible. Such a further component can also be formed, e.g., by a“sleeve” or the like, which is arranged on the outer circumference ofthe crucible, instead of by an outer crucible.

In a further development of the embodiment, which provides for apositive engagement of a protrusion with a depression, it is providedthat the depression and/or the protrusion has a round cross sectionalsurface, viewed in a plane orthogonally to the direction of theengagement. The cross sectional surface can represent, e.g., an at leastapproximately circular cross sectional surface, for the purpose of whichthe depression and the protrusion can, e.g., each be configured in an atleast approximately frustoconical or approximately hemispherical manner.A lateral dimension (e.g., diameter) of the round cross sectionalsurface can be, e.g., in the range of between 1 and 3 mm.

In another further development of the embodiment providing a positiveengagement of a protrusion with a depression, it is provided that thedepression and/or the protrusion has an elongated cross sectionalsurface, viewed in a plane orthogonally to the direction of theengagement.

The elongated cross section surface can run, e.g., at leastapproximately in the vertical direction (e.g., with a length in therange of between 1 and 5 mm) and/or can have a width in the range ofbetween 0.5 mm and 3.0 mm, viewed in a circumferential direction of thecrucible. The depression can form, e.g., a groove, which runs in astraight line, with which a rib engages, which is dimensioned to fit andwhich runs in a straight line. A straight course of the above-mentionedelongated cross sectional surface of the depression and, correspondingthereto, of the protrusion, is preferably oriented in the verticaldirection of the measuring arrangement. It is further preferred when thedepression and, corresponding thereto the protrusion, have a roundeddepression bottom or a rounded protrusion end, respectively. In thealternative or in addition, it can be provided, e.g., that a crosssection of the depression and, corresponding thereto, a cross section ofthe protrusion, decrease, viewed in the engagement direction.

It is provided in one embodiment of the invention that a top side of thesensor has a sensor edge protruding upwards or a different edgelimitation (which is, e.g., not connected directly to the sensor),whereby a centering of the outer crucible on the sensor can thereby berealized, e.g., in a highly advantageous manner by means of positiveconnection.

The sensor edge (or a different edge limitation, respectively), can beembodied so as to extend across the entire circumference of the sensorso as to be closed, e.g., in a ring-shaped manner. Alternatively,however, the sensor edge protruding upwards (or the edge limitation,respectively), can also be embodied, e.g., only at individual locationsof the circumference, e.g., at three (or more) locations distributedequidistantly across the circumference, viewed across the circumferenceof the sensor.

In the alternative or in addition to the accomplishing the mentionedcentering of the crucible, whether directly by attaching an outer sideof the crucible to the sensor edge (or other edge limitation,respectively), or indirectly by attaching an outer side of an outercrucible, which receives the crucible, to the sensor edge (or other edgelimitation, respectively), a visible marking (e.g., marking protrusionor marking depression) of the above-mentioned type and/or a protrusionor a depression, respectively, for the above-mentioned positiveengagement (for ensuring the predetermined rotational position of thecrucible) can also be embodied on the sensor edge (or other edgelimitation, respectively), in an advantageous manner.

Returning once more to the further development of the invention with useof an outer crucible, it is provided in one embodiment that a bottom ofthe outer crucible abuts completely on a bottom of the crucible. Forthis purpose, a configuration, which corresponds to a configuration onthe outer side of the crucible bottom, is to be provided on the innerside of the outer crucible bottom. The complete abutment has theadvantage of a good thermal contact between crucible and outer crucible.It is provided in another embodiment that a bottom of the outer crucibleabuts on a bottom of the crucible only on one or a plurality of contactsurfaces, the total surface of which is significantly smaller than atotal surface of the inner side of the outer crucible bottom (e.g.,smaller than 50%, in particular smaller than 25% of this surface). It isprovided in one embodiment that a bottom of the outer crucible abuts ona bottom of the crucible along a ring-shaped contact surface. Thering-shaped contact surface can thereby in particular be smaller than50%, in particular smaller than 25%, of the total surface of the innerside of the outer crucible bottom. Such a “partial” abutment has theadvantage that a better-defined or well-reproducible thermal contact,respectively, between crucible and outer crucible is generally attainedeven in the presence of certain production tolerances and/or, e.g.,thermal shape changes. It is provided in one embodiment that a jacket ofthe outer crucible abuts completely on a jacket of the crucible. Forthis purpose, a configuration, which corresponds to a configuration onthe outer side of the crucible bottom jacket, is to be provided on theinner side of the outer crucible jacket. The complete abutmentcontributes to a good thermal contact between crucible and outercrucible, and additionally realizes a centering of the crucible in theouter crucible in an advantageous manner. It is provided in oneembodiment that the outer crucible and the crucible are configured insuch a way that a centering of the crucible in the outer crucible isthereby realized by means of positive connection. This measurecontributes to an improved reproducibility of the measuring conditions,e.g., in the case that the crucible is removed from the outer cruciblein order to then insert the crucible into a different outer crucible(for a different measurement) or to insert a different crucible into theouter crucible. A height of the outer crucible is preferably dimensionedin such a way that the outer crucible overlaps 1% to 60%, in particular10% to 40% of a height of the crucible. It is provided in one embodimentthat the outer crucible material is a metal or a metal alloy, inparticular tungsten or a tungsten alloy. It is provided in anotherembodiment that the outer crucible material is a ceramic material, inparticular a ceramic material on the basis of Al₂O₃ or Y₂O₃. A goodmaterial compatibility of the outer crucible material towards therespective crucible as well as towards the respective sensor (or the topside thereof, respectively), can be ensured in an advantageous mannerwith the use of one of the two above-mentioned materials as outercrucible material, metal or metal alloy or ceramic material,respectively, for most of the applications and often up to hightemperatures. In one embodiment, the crucible (or at least the bottomthereof, respectively) is made of graphite. In particular in this case,the outer crucible material can advantageously be selected, e.g., as ametal or a metal alloy. In one embodiment, the respective cruciblematerial is a ceramic material. In particular in this case, the outercrucible material can advantageously be selected, e.g., as a metal ormetal alloy. In one embodiment, the respective crucible material is ametal or a metal alloy. In particular in this case, the outer cruciblematerial can advantageously be selected, e.g., as a ceramic material. Inthe alternative, graphite, e.g., can also be considered. In oneembodiment, the sensor is made of a metal or a metal alloy (at least inthe area contacted by the outer crucible). In particular in this case,the outer crucible material can advantageously be selected, e.g., as aceramic material. In one embodiment, the sensor is made of a ceramicmaterial in the relevant area. In particular in this case, the outercrucible material can advantageously be selected, e.g., as a metal or ametal alloy.

In the case of some material combinations relating to the cruciblematerial and the sensor material, an even further improvement can beattained in the context of a further development of the invention inthat an inserted “washer arrangement”, which has a “first layer”, whichcontacts the crucible, of a first material, and a “second layer”, whichcontacts the sensor, of a second material, which differs from the firstmaterial is provided between the crucible and the sensor, wherein thefirst layer is formed by the outer crucible and the first material isaccordingly formed by the outer crucible material, whereas the secondlayer is formed by an additional layer or additional washer,respectively (between outer crucible and sensor).

In the case of this further development, the outer crucible and a“second washer” (second layer) can advantageously originate, e.g., froman “outer crucible washer set”, which includes at least one outercrucible and a plurality of second washers and/or at least a secondwasher and a plurality of outer crucibles. The washer arrangement of themeasuring arrangement according to the invention thereby preferablyconsists of the outer crucible and the second washer, i.e., withoutfurther washers(s) between crucible and sensor.

It is provided in a modification that the washer arrangement is acomposite washer construction, which includes the outer crucible and thesecond layer so as to be connected to one another (in particular, e.g.,non-detachably). The washer arrangement is thus advantageously assembledso as to already be “ready for use”. The composite washer constructionpreferably includes only the outer crucible and the second layer. It isnot to be ruled out, however, that a further layer is includedtherebetween, the material of which differs from the outer cruciblematerial as well as from the material of the second layer (e.g., actingas an “adapter layer”, on both sides of which the outer cruciblematerial and the second material can be connected particularly well).

It is provided in another further development of the invention(alternatively or additionally to the use of an “outer crucible”) thatthe measuring arrangement further has a “washer arrangement”, which isinserted between the crucible and the sensor and which has a firstlayer, which contacts the crucible, of a first material, and a secondlayer, which contacts the sensor, of a second material, which differsfrom the first material. Such a “washer arrangement”, i.e., one orplurality of washers, makes it possible in an advantageous manner toavoid a direct contact between the crucible and the sensor, so that areaction between crucible and sensor material is avoided. The firstlayer contacting the crucible can be made of a first material, which isparticularly well compatible with the crucible material, whereas thesecond layer contacting the sensor can be made of a second material,which is particularly well compatible with the respective sensormaterial. The washer arrangement is advantageously embodied in such away that, in the situation of use, the crucible only contacts the firstlayer and the sensor only contacts the second layer. A height of thewasher arrangement can in particular lie, e.g., in a range of between100 and 500 μm. It is provided in one embodiment that the washerarrangement has a first washer forming the first layer and, separatelytherefrom, a second washer forming the second layer. It is provided inanother embodiment that the washer arrangement is a composite washer,which includes the first layer and the second layer so as to beconnected to one another (in particular, e.g., non-detachably). Thelateral expansion of the washer arrangement, in combination with asensor, which has the mentioned protruding sensor edge or a differentedge limitation, can in particular be dimensioned in such a way, e.g.,that a centering of the washer arrangement on the sensor is realizedthereby by means of positive connection. In a preferred embodiment ofthe washer arrangement, the first layer and the second layer of thewasher arrangement (and thus generally the entire washer arrangement),viewed in the top view, each have a circular contour. It is provided inone embodiment that the first material or the second material is a metalor a metal alloy, in particular tungsten or a tungsten alloy. It isprovided in one embodiment that the second material or the firstmaterial is a ceramic material, in particular a ceramic material on thebasis of Al₂O₃ or Y₂O₃. In one embodiment, the crucible (or at least thebottom thereof, respectively) is made of graphite. In particular in thiscase, the first material can advantageously be selected, e.g., as ametal or a metal alloy. In one embodiment, the respective cruciblematerial is a ceramic material. In particular in this case, the firstmaterial can advantageously be selected, e.g., as a metal or metalalloy. In one embodiment, the respective crucible material is a metal ora metal alloy. In particular in this case, the first material canadvantageously be selected, e.g., as a ceramic material. In thealternative, graphite, e.g., can also be considered. In one embodiment,the sensor is made of a metal or a metal alloy (at least in the areacontacted by the outer crucible). In particular in this case, the secondmaterial can advantageously be selected, e.g., as a ceramic material. Inone embodiment, the sensor is made of a ceramic material in the relevantarea. In particular in this case, the second material can advantageouslybe selected, e.g., as a metal or a metal alloy.

According to a further aspect of the invention, the above-given objectin the case of a method for the thermal analysis of a sample of theabove-mentioned type is solved in that a measuring arrangement of thetype described here is used in the sample chamber for arranging thesample and for measuring the sample temperature. The embodiments andparticular designs described here for the measuring arrangementaccording to the invention can be provided individually or in anycombination, analogously also as embodiments or particular designs,respectively, of the method for the thermal analysis according to theinvention.

In one embodiment, the method according to the invention comprises anarranging of the crucible on the sensor, wherein the crucible isarranged in the predetermined rotational position of the crucible withrespect to the sensor.

In one embodiment, the arranging of the crucible on the sensor takesplace with the help of an aligning of a visible marking, which isprovided in the area of the outer side of the crucible. The aligning canthereby take place, e.g., at a further marking of the measuringarrangement, which is provided in the area of the sensor or at acomponent of the measuring arrangement, which is arranged in astationary manner to the sensor (arranging the crucible on the sensor insuch a way that the two markings “are brought into alignment” withregard to the angle of rotation).

In one embodiment, the arranging of the crucible on the sensor takesplace with the help of an engagement of a protrusion with a depression,wherein the protrusion is arranged on the sensor or a further componentof the measuring arrangement, which is arranged in a stationary mannerto the sensor, and the depression is arranged in the area of the outerside of the crucible, or vice versa.

The predetermined rotational position of the crucible with respect tothe sensor is thus ensured in a particularly advantageous manner bymeans of a positive engagement.

In one embodiment, the arranging of the crucible on the sensoradditionally comprises a centering of the crucible with respect to thesensor, wherein this centering can in particular be realized by means ofa positive connection (e.g., in the case of a crucible of a certaincontour in a matching receiving chamber, which is defined by a sensoredge protruding upwards or another edge limitation for a lower end ofthe crucible).

In the alternative or in addition to accomplishing the mentionedcentering of the crucible, whether directly by attaching an outer sideof the crucible to the sensor edge (or other edge limitation,respectively), or indirectly by attaching an outer side of an outercrucible, which receives the crucible, to the sensor edge (or other edgelimitation, respectively), a visible marking (e.g., marking protrusionor marking depression) of the above-mentioned type and/or a protrusionor a depression, respectively, for the above-mentioned positiveengagement (for ensuring the predetermined rotational position of thecrucible) can also be embodied on the sensor edge (or other edgelimitation, respectively), in an advantageous manner.

The “temperature control of the sample” can generally include a heatingup and/or cooling down of the sample, wherein temporal phases canfurthermore also be provided, in the case of which the temperatureprogram, which forms the basis for the temperature control, provides aconstant temperature. In one embodiment, the temperature program definesthe chamber temperature in the interior of the sample chamber, for thepurpose of which the method can comprise, e.g., a measuring of thechamber temperature and, based thereon, a control of a temperaturecontrol device, preferably by means of a regulation (e.g., PIDregulation) of the chamber temperature. Deviating from this, thetemperature program can alternatively also define a predeterminedtemporal course of the sample temperature, for the purpose of which thecorresponding control (in particular regulation) of the temperaturecontrol device can take place accordingly, e.g., based on the measuredsample temperature.

The method preferably comprises a recording of measuring data in thecourse of the temperature program, in particular of data, whichrepresents the temperature-dependent and/or time-dependent course of atleast one temperature of chamber temperature and sample temperature (andpreferably both). By evaluation of such data during the temperaturecontrol and/or after conclusion of the temperature program, the at leastone property (e.g., material parameter), which is of interest inresponse to the thermal analysis, of the sample subjected to the methodcan be determined.

As a function of the thermal analysis, which is to be performedconcretely, it can be provided in the case of the method according tothe invention that two measuring arrangements comprising ananti-rotation protection of the described type are arranged in thesample chamber, i.e. two sensors of the described type each comprising acrucible of the described type arranged thereon. In the method, bothcrucibles or possibly also two samples (e.g., “actual sample” and“reference sample”), respectively, can simultaneously be subjected to ajoint temperature control in the sample chamber in this case. As analternative to the simultaneous temperature control of two samples, thesecond crucible can also be used, e.g., “empty” (i.e., without sample orreference sample stored therein, respectively), during the methodaccording to the invention.

It goes without saying that in most of the applications, these twomeasuring arrangements should be embodied identical to each other in thecase of such a use of two measuring arrangements of the described typein the case of the method for the thermal analysis.

At at least one point in time, the chamber temperature reaches a minimumvalue in the course of the temperature program and the chambertemperature reaches a maximum value at at least a different point intime.

The use of the invention is particularly advantageous, when at least onecrucible is removed at least once from the sensor and the same oranother crucible is subsequently arranged on the sensor again as part ofthe performance of a series of measurements of thermal analyses (e.g.,after an exchange of the sample and/or other change at the respectivemeasurement arrangement, such as, e.g., adding/removing/exchanging anouter crucible, adding/removing exchanging at least one washer etc.).

It is provided in one embodiment that the chamber temperature has amaximum value of at least 500° C. in the course of the temperatureprogram. For many applications, the maximum value can also be at least750° C. or even at least 1000° C. On the other hand, it is sufficientfor most of the applications to provide a maximum value of the chambertemperature of maximally 2000° C. in the course of the temperatureprogram. With regard to the minimum value in the course of thetemperature program, it can lie, e.g., at “room temperature” or slightlyabove it (e.g., in the range of between 20° C. and 100° C.), inparticular when a temperature control device used in the case of themethod does not provide an option for cooling below the roomtemperature. Apart from that, a minimum value of the chamber temperaturein the range of, e.g., −150° C. to 100° C. can readily be realized formost of the applications (e.g., by means of Peltier cooling and/or,e.g., cooling by means of liquid nitrogen).

In a particularly advantageous embodiment, the method for the thermalanalysis is a DSC (differential scanning calorimetry) method, for thepurpose of which the described measuring arrangement is present twice inthe sample chamber and in particular a time-dependent course of adifference of the temperatures, which are measured by means of the twosensors, is determined in response to the evaluation of a measuringresult (e.g., the already mentioned measuring data), in particular so asto thus be able to determine energetic effects and/or, e.g., atemperature-dependent specific heat capacity of the sample.

In a further development, the method for the thermal analysis accordingto the invention combines a DSC with at least one furtherthermo-analytical method, such as in particular, e.g., a TGA(thermogravimetric analysis).

In one embodiment, the method for the thermal analysis is a “hightemperature” DSC, or a combination of “high temperature” DSC and TGA,wherein the chamber temperature and/or the sample temperature has amaximum value of at least 500° C., in particular at least 750l20 C., oreven at least 1000° C., in the course of the temperature program.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described below by means of exemplaryembodiments with reference to the enclosed drawings. In each caseschematically:

FIG. 1 shows a measuring arrangement for a thermal analysis of a sample,comprising a crucible and a sensor, according to an embodiment of theprior art,

FIG. 2 shows a measuring arrangement similar to that of FIG. 1, butaccording to a modified exemplary embodiment,

FIG. 3 shows a measuring arrangement similar to that of FIG. 1, butaccording to a modified exemplary embodiment,

FIG. 4 shows a measuring arrangement similar to that of FIG. 1, butaccording to a modified exemplary embodiment,

FIG. 5 shows a measuring arrangement according to a further exemplaryembodiment,

FIG. 6 shows a measuring arrangement according to a further exemplaryembodiment,

FIG. 7 shows a measuring arrangement according to a further exemplaryembodiment,

FIG. 8 shows a measuring arrangement according to a further exemplaryembodiment,

FIG. 9 shows a measuring arrangement according to a further exemplaryembodiment,

FIG. 10 shows a measuring arrangement according to a further exemplaryembodiment,

FIG. 11 shows a cross sectional contour of a crucible according to anexemplary embodiment (according to the invention), which can be used inthe case of a measuring arrangement, and

FIG. 12 shows a cross sectional contour similar to that of FIG. 11, butaccording to a modified exemplary embodiment (according to theinvention).

DETAILED DESCRIPTION

FIG. 1 shows a schematic side view of a measuring arrangement, the setupof which is known from the prior art, for a thermal analysis of a sampleP. The measuring arrangement has a crucible 10 for storing the sample Pin a crucible 10 as well as a sensor 20 for measuring a sampletemperature of the sample P when the crucible 10 is arranged on thesensor 20.

The crucible 10 is made of a crucible material, such as typically, e.g.,graphite or metal and has a circular cylindrical form in the illustratedexemplary embodiment comprising a circular disk-shaped bottom 12, to theedge of which a cylindrical jacket 14 protruding upwards is attached.

Terms, such as “top” or “top side”, respectively, “bottom” or “bottomside”, respectively, “laterally”, etc. used here in each case refer tothe arrangement of the respective component in the situation of use (inresponse to performing the thermal analysis).

The crucible 10 can (optionally) further have a cover 16, which isillustrated in a dashed manner in FIG. 1, which closes the interior ofthe crucible 10, which is otherwise open to the top and is limited bybottom 12 and jacket 14. In some applications, a hole is embodied insuch a cover 16 in order to provide for a pressure compensation betweenthe interior including the sample P and an exterior space of thecrucible 10.

In the situation of use of the measuring arrangement, the sensor 20 isused in order to be able to arrange a crucible, such as, e.g., theillustrated crucible 10, thereon and to thus arrange the crucibletogether with sample P, which may be included (including “referencesample”) in a sample chamber in a defined manner, and to measure atemperature on the bottom side of the crucible 10 or thus the sampletemperature (in the case of the crucible 10 containing the sample P),respectively. The latter requires a more or less low heat transferresistance emanating from the sample P, further across the bottom 12 ofthe crucible 10 to the actual temperature measuring device (e.g.,thermal element) on the surface or in the interior of the sensor 20.

In the illustrated exemplary embodiment, the sensor 20 has the form of acircular even disk of uniform thickness, so that a good thermal contactbetween sample P and sensor 20 results in interaction with the bottom 12of the crucible 10, which is also circular disk-shaped.

Deviating from the illustrated complete abutment of the bottom 12 on thetop side of the sensor 20, a different thermal contacting, however,could also be provided, for example along a ring-shaped contact surfacebetween the bottom 12 and the sensor 20, e.g., in that the bottom 12 asa whole or at least on its bottom side is provided with a recess or acurvature.

In the illustrated example, a lateral expansion of the sensor 20,measured as the diameter of the circular disk form, is at least as largeas or, as illustrated, even larger than a corresponding lateralexpansion of the crucible 10 in the area of the bottom 12 thereof.

All of the features of the crucible 10 and of the sensor 20 describedabove with regard to the exemplary embodiment of FIG. 1, includingrespective described modifications, can also be provided in the case ofthe crucible or the sensor, respectively, of a measuring arrangementaccording to the present invention. Exemplary embodiments of the presentinvention will be described further below with reference to FIGS. 11 and12.

It is disadvantageous, for example, in the case of the known measuringarrangement illustrated in FIG. 1 that there is no well-definedarrangement position of the crucible 10 on the sensor 20, viewed in thelateral (horizontal) direction, so that the reproducibility ofcorresponding measuring processes of the thermal analysis is impacted inparticular in response to repeated removal and new rearrangement of thecrucible 10 on the sensor 20.

It is also disadvantageous that the crucible 10 can be arranged in anarbitrary or random rotational position, respectively, with respect tothe sensor 20. This also impacts the reproducibility of measurementsperformed by means of this measuring arrangement.

Finally, a further disadvantage is, e.g., the risk of damage or evendestruction of the sensor 20 by means of chemical and/or physicalreactions on the contact surface existing between the crucible materialand the sensor material (An analogous problem furthermore results forthe contact surface between sample material and crucible material).

FIGS. 2 to 4 show several exemplary embodiments, which are modified ascompared to the example of FIG. 1 and which are based on applicant'sinternal prior art.

In the following description of the exemplary embodiments according toFIGS. 2 to 4, as well as the further exemplary embodiments according toFIGS. 5 to 12, the same reference numerals are used for components ofthe respective measuring arrangement, which have the same effect.Essentially only the differences to the already described exemplaryembodiment or embodiments, respectively, is discussed thereby andreference is hereby moreover expressly made to the description of thepreceding exemplary embodiments.

FIG. 2 shows a measuring arrangement comprising a crucible 10 and asensor 20, wherein as compared to the example of FIG. 1, however, afirst modification lies in that an “inner crucible” 18 is insertedbetween an e.g., metallic sample P and the, e.g., metallic crucible 10,in order to avoid reactions between the material of the sample P and thematerial of the crucible 10 at high temperatures. In the illustratedexample, the inner crucible 18 is made of a ceramic material.

With regard to the configuration of such an inner crucible, it ispreferably adapted to the configuration of the crucible 10, as in thecase of the illustrated inner crucible 18, for an abutment (of the outerside of the inner crucible 18 on the inner side of the crucible 10),which is as well-defined as possible and/or as complete as possible.Similar to the crucible 10, the illustrated inner crucible 18 has acircular disk-shaped bottom and a cylindrical jacket attached thereto soas to protrude upwards, wherein the bottom as well as the jacket eachabut completely on the respective inner side of the bottom or of thejacket of the crucible 10, respectively, in the illustrated example.

This modification has the advantage, e.g., that a larger freedom iscreated in response to the selection of the crucible material of thecrucible 10.

A second modification lies in that the measuring arrangement further hasa washer 30-1, which is inserted between the crucible 10 and the sensor20 and which has a top side contacting the crucible 10 on the bottom 12thereof and a bottom side contacting the sensor 20 on the top sidethereof.

This modification has the advantage, e.g., that a larger freedom iscreated thereby in response to the selection of the crucible materialand of the sensor material.

In the illustrated example, the washer 30-1 is made of a ceramicmaterial. A diffusion welding and a chemical reaction between thecrucible material and the sensor material of the sensor (which isgenerally very “valuable”) is prevented by means of the washer 30-1,which is highly advantageous in particular in situations of use withrelatively high temperatures occurring thereby.

The examples according to FIGS. 1 and 2 also have the disadvantage thatthe crucible 10 is not self-centered with respect to the sensor 10, butthat the crucible 10 can shift, e.g., or can be arranged, e.g., indifferent lateral positions on the sensor 20 by a user, respectively,which has a disadvantageous effect on the reproducibility ofmeasurements performed in the context of the thermal analysis.

To avoid this disadvantage, embodiments can be considered, which areshown in an exemplary manner in FIGS. 3 and 4.

FIG. 3 shows a measuring arrangement, which, as compared to the exampleof FIG. 1, is modified in that the top side of the sensor 20 has asensor edge 22, which protrudes upwards, and that a centering of thecrucible 10 on the sensor 20 is thus realized by means of positiveconnection. The sensor edge 22 can be embodied, e.g., extending acrossthe entire circumference of the sensor 20 so as to be closed in aring-shaped manner.

Deviating from the embodiment according to FIG. 3, the sensor edge 22protruding upwards could also be embodied only at individual locationsof this circumference, viewed across the circumference of the sensor 20.

Deviating from the illustrated example, the positive connection can alsobe realized by means of a different edge limitation instead of by meansof the sensor edge 22, which is to be understood to be a component ofthe measuring arrangement, which is arranged to be stationary withrespect to the sensor 20 in such a way that said measuring arrangementrepresents a limitation for the crucible 10, viewed in the lateraldirection, with regard to the arrangeability thereof on the sensor 20.

FIG. 4 shows a measuring arrangement, in the case of which the top sideof a sensor 20 has a sensor edge 22, which protrudes upwards (similar toFIG. 3), so that a centering of the crucible 10 on the sensor 20 is thusrealized again by means of positive connection. A washer 30-1 (similarto FIG. 2) is also provided, whereby, compared to the example of FIG. 2,a modification lies in that the washer 30-1 is decreased in the lateralexpansion thereof to the extent that it can fit in the space defined bythe sensor edge 22.

In practice, however, not all desired sensor-crucible-sample-materialcombinations can be accomplished with the help of an inner crucible 18and/or a washer 30-1 with regard to unwanted reactions between sensorand crucible as well as between crucible and sample. For example, somesamples have to be arranged in a crucible 10 made of graphite, wherebyreactions with the sensor 20 can occur at high temperatures. Even thougha ceramic washer 30-1 resolves this issue to a certain extent, it canreact with the graphite crucible at very high temperatures.

To avoid this problem, embodiments can be provided, which will bedescribed below in an exemplary manner with reference to FIGS. 5, 6, 8and 10.

FIG. 5 shows a measuring arrangement comprising a crucible 10 and asensor 20, wherein, compared to the example of FIG. 1, it is a specialfeature that the measuring arrangement further has a washer arrangement30, which is inserted between the crucible 10 and the sensor 20 andwhich has a first layer 30-1, which contacts the crucible 10, of a firstmaterial, and a second layer 30-2, which contacts the sensor 20, of asecond material, which differs from the first material.

The washer arrangement 30 can thereby have a first washer forming thefirst layer 30-1 and, separately therefrom, a second washer forming thesecond layer 30-2.

This alternative can also be viewed as modification of the example ofFIG. 2, wherein the difference of the embodiment according to FIG. 5then lies in that a further (second) washer (layer 30-2) is insertedbetween the crucible 10 and the sensor 20.

In the case of this alternative, it can be provided, in particular inthe case of graphite as crucible material, that the first washer orfirst layer 30-1, respectively, is made of a metallic material (e.g.,tungsten or, e.g., tungsten alloy) and the second washer or second layer30-2, respectively, is made of a ceramic material.

Deviating therefrom, an alternative is also possible in FIG. 5, in thecase of which the washer arrangement 30 is a composite washer, whichincludes the first layer 30-1 and the second layer 30-2 so as to beconnected to one another (e.g., welded to one another).

This alternative is well suited, e.g., for the case that the firstmaterial and the second material can be welded to one another, thus,e.g., that a suitable combination of two metals or metal alloys,respectively, is selected for this purpose.

The layers of the composite washer, which are connected to one another,can also be embodied in such a way, e.g., that the one layer is embodiedas a sputter layer on the other layer.

In the example of FIG. 5, the sensor 20 is furthermore embodied with asensor edge 22, which protrudes upwards, of the type, which has alreadybeen described (with reference to FIGS. 3 and 4), whereby a centering ofat least the second layer 30-2 or the washer arrangement 30 as such iscentered on the sensor, respectively, when using a composite washer(layers 30-1 and 30-2 connected to one another).

In the example of FIG. 5, the lateral expansion of the first layer 30-1is furthermore selected to be smaller than the lateral expansion of thesecond layer 30-2, so as to reliably avoid a contact of the first layer30-1 to the sensor 20 (on the sensor edge 22) by means of a lateralprotrusion of the circumference of the second layer 30-2 all around thecircumference of the first layer 30-1.

In order to in particular prevent a shifting or an incorrectpositioning, respectively, of the top layer 30-1 even in the case of aseparate design of the two layers 30-1 and 30-2, or in order to thenalso realize a centering of the top disk 30-1, respectively, deviatingfrom FIG. 5, an embodiment, as it is shown in an exemplary manner inFIG. 6, can be used.

FIG. 6 shows a measuring arrangement comprising a crucible 10 and asensor 20, wherein, as compared to the example of FIG. 5, a modificationlies in that the first layer 30-1 in the washer arrangement 30 isembedded on a top side of the second layer 30-2.

It is thereby provided in the example of FIG. 6 that the first layer30-1 in the washer arrangement 30 protrudes upwards beyond the secondlayer 30-2. The first washer or layer 30-1, respectively, protrudesupwards slightly beyond the edge of the second washer or layer 30-2,respectively, so that an unwanted contact between the crucible 10 (e.g.,of graphite) and the layer 30-2 (e.g., of ceramic material) is ruledout.

In addition to the embodiment with two washers, which are separate fromone another, a composite washer, e.g., in the case of which one isformed by first layer 30-1 and second layer 30-2 by means of sputteringor otherwise coating (e.g., the respective other one of these twolayers), can in particular be considered with regard to the washerarrangement (with layers 30-1, 30-2) described in FIGS. 5 and 6 (as wellas below in the case of FIGS. 8 and 10). For example, the first layer30-1 can be made of a metallic material (metal or metal alloy) on thetop side of a ceramic second layer 30-2 by means of sputtering.

The stacking of two separate washers 30-1, 30-2 has the advantages thateach individual washer can also be used alone (or in combination with adifferent second washer), depending on the application, and that, in thecase of a contamination of one of the washers (in particular, e.g., ofthe washer 30-1), only the latter needs to be exchanged. In the lattercase, the contaminated layer would quasi be a useful layer, which can bereplaced easily and cost-efficiently.

The described washer arrangement is in particular advantageous inapplications, in the case of which the crucible material is graphite andthe sensor material is a metallic material. Deviating therefrom,however, a crucible of metallic material (in particular, e.g., tungstenor tungsten alloy), e.g., can also be provided and/or an additionalinner crucible (in particular, e.g., of graphite).

FIG. 7 shows a measuring arrangement comprising a crucible 10 and asensor 20, with the special feature that the measuring arrangementfurther has an “outer crucible” 30-1 for storing the crucible 10 in theouter crucible 30-1, wherein the crucible 10 is made of a cruciblematerial and the outer jacket 30-1 is made of an outer cruciblematerial, which differs from the crucible material.

In contrast to the examples of FIG. 2 and FIG. 4, a modification lies inthat said “outer crucible” 30-1 (FIG. 7) is provided instead of an evenplate-shaped “washer” 30-1 (FIGS. 2 and 4), in order to avoid a contactbetween the crucible material and the sensor material.

It is important to note in this regard that an “outer crucible” in termsof the invention consists of a base body or comprises a base body,hereinafter also referred to as “outer crucible body”, which has atleast approximately the shape of a shell or of a cup, wherein, withregard to the intended purpose (storing the crucible), the outercrucible body has at least one section, which will be referred to as(outer crucible body) “jacket”, which represents a lateral limitation ofthe outer crucible body, and can optionally have a section, which willbe referred to as (outer crucible body) “bottom”, which represents alower end section of the outer crucible body facing the sensor (insituation of use), and which is connected on the bottom side of thejacket. An interior of the outer crucible, which is limited by thejacket (and the bottom, which may be present) on the inner side of thejacket, is to be dimensioned in such a way thereby that the crucible ofthe measuring arrangement can be stored therein.

In the case of the exemplary embodiment of FIG. 7, the outer crucible30-1 has a circular cylindrical shape comprising a circular disk-shapedbottom, to the edge of which a cylindrical jacket is attached so as toprotrude upwards.

In the illustrated example, the bottom of the outer crucible 30-1 abutscompletely on a bottom 12 of the crucible 10. In the alternative,however, it could also be provided, e.g., that the bottom of the outercrucible 30-1 abuts on the bottom 12 of the crucible 10 along arings-shaped contact surface.

This can be realized, e.g., in that, deviating from the exampleaccording to FIG. 7, the bottom 12 as a whole or at least on its bottomside is provided with a recess or a curvature. In the alternative or inaddition, the bottom of the outer crucible 30-1, e.g., could be providedwith a corresponding recess or curvature on the top side thereof. It canfurthermore be considered, e.g., to provide a material cutout(depression or even a through opening in the bottom) in a central area,viewed laterally, of the bottom of the outer crucible 30-1, so that thecrucible 10 now bears on a circular ring-shaped bottom section of theouter crucible 30-1.

It is important to note in this context that the outer crucible,deviating from the example according to FIG. 7, could also be configuredcompletely without a bottom, in particular, e.g., comprising a jacket,which tapers from the top to the bottom in the vertical direction, onthe inner side of which the respective crucible bears and is thusstored. It is preferred in the case of this alternative that therespective sensor does not have a largely even top side, as is shown inFIG. 7, but has an (e.g., circular) recess or cutout in a central area,viewed laterally, on the edge of which the outer crucible bears (e.g.,extending so as to be closed in a ring-shaped manner). The recess orcutout, respectively, of the sensor can thereby be dimensioned orconfigured to be so deep, respectively, that no section of therespective crucible contacts the sensor, even if a section of thecrucible protrudes downwards beyond a lower end of the outer cruciblejacket.

Returning to the example of FIG. 7, it is provided in the case of thisexample that the jacket of the outer crucible 30-1 abuts completely onthe jacket 14 of the crucible 10. In other words, an inner diameter ofthe jacket of the outer crucible 30-1, in adaptation on an outerdiameter of the jacket 14, is dimensioned in such a way here that thecrucible 10 can be inserted into the outer crucible 30 with little play,at most.

Such a complete abutment between the jacket of the crucible and thejacket of the outer crucible can (contrary to FIG. 7) also be providedin an advantageous manner, when both jackets taper, e.g., viewed fromthe top down, for example when both have a frustoconical configuration(with identical angle of inclination).

In the case of such embodiments, a design can advantageously also beprovided, which is also realized in the case of the example of FIG. 7and which lies in that the outer crucible and the crucible areconfigured in such a way that a centering of the crucible in the outercrucible is realized thereby by means of positive connection. Thismeasure improves the reproducibility of the measurements performed bymeans of the measuring arrangement.

In the case of the shown example of FIG. 7 it is furthermore providedthat the outer crucible 30-1 overlaps approximately 30% of a height ofthe crucible 10. Such an overlap in the range of 10% to 40% is preferredfor the most part.

Under the exemplary assumption that the crucible 10 as well as thesensor 20 are each made of a metallic material, in particular ceramicmaterial, e.g., is suitable as outer crucible material. The outercrucible 30-1 quasi takes over the role of the washer 30-1 shown in FIG.2 in this case (only that no inner crucible is provided in the case ofthe example of FIG. 7). The outer crucible (FIG. 7) advantageously alsoprevents an unwanted contact between the crucible 10 and the sensor 20on the side of the crucible 10.

FIG. 8 shows a measuring arrangement comprising a crucible 10 and asensor 20, wherein a modification as compared to the example of FIG. 7lies in that the measuring arrangement further has a washer 30-2, whichis inserted between the outer crucible 30-1 and the sensor 20.

As compared to the embodiment according to FIG. 7, in particular theadvantage is achieved that a larger freedom is created in response tothe selection of the crucible material and/or sensor material by meansof this measure.

According to an alternative approach, the example of FIG. 8 can also beconsidered to be a modification of the already described embodimentscomprising “washer arrangement” (see FIGS. 5, 6 and 10). In the case ofthis approach, the outer crucible 30-1 or at least the bottom thereof,respectively, embodies the “first layer” 30-1 of a washer arrangement30, and the washer 30-2 embodies a “second layer” 30-2 of the washerarrangement 30.

With regard to this alternative approach, it is further noted that,deviating from the example according to FIG. 8, the two components 30-1,30-2 could also be provided so as to be connected to one another (e.g.,non-detachably). A connection of the components 30-1, 30-2 can therebybe embodied/realized, e.g., in such a way, as it has already beendescribed for a “composite washer”.

In the case of the measuring arrangements shown in FIGS. 7 and 8, thecrucible 10 is not self-centering with respect to the sensor 20. Torealize this, embodiments can be used, which are illustrated in anexemplary manner in FIGS. 9 and 10.

FIG. 9 shows a measuring arrangement comprising a crucible 10 and asensor 20, whereas, as compared to the example of FIG. 7, a modificationlies in that a centering of an outer crucible 30-1 is realized on thesensor 20 by means of the sensor edge 22 by means of positiveconnection.

In the case of the example of FIG. 9, the outer crucible 30-1 iscentered by means of the direct abutment thereof on the sensor edge 22.In the case of a circular cylindrical configuration of the outercrucible 30-1 and of the sensor edge 22 protruding upwards, as assumedhere, this represents a corresponding dimensioning between an outerdiameter of the outer crucible 30-1 and an inner diameter of the sensoredge 22.

FIG. 10 shows a measuring arrangement comprising a crucible 10 and asensor 20, wherein, as compared to the example of FIG. 8, a modificationlies in that the washer 30-2 (or the second layer 30-2, respectively, ofthe washer arrangement 30) is centered on the sensor 20 by means of thesensor edge 22 by means of positive connection. A further modificationlies in that an “embedding” (of the type as already described withreference to FIG. 6) of the outer crucible 30-1 (or of the first layer30-1, respectively) is provided on the top side of the washer 30-2 (orof the second layer 30-2, respectively).

In an alternative approach, the embodiment according to FIG. 10 can alsobe considered to be a modification as compared to the example of FIG. 6,which consists in that an outer crucible 30-1 (FIG. 10) is providedinstead of the first layer 30-1 (FIG. 6), whereby a centering of thecrucible 10 is ultimately attained in this example.

In the case of the example of FIG. 10, the outer crucible 30-1, similaras in the case of FIG. 9, is centered on the sensor 20 by means of apositive connection, but not by means of a direct abutment of the outercrucible 30-1 on the sensor edge 22, but indirectly via the visiblecentering of the washer 30-2 (or second layer 30-2, respectively, of awasher arrangement 30). The washer 30-2 abuts directly on the sensoredge 22.

With regard to the outer crucible material, the latter can be suitablyselected in an advantageous manner for a corresponding materialcompatibility with the material of the respective crucible 10 and thematerial adjoining downwards, e.g., sensor material or possibly materialof a washer 30-2 or second layer 30-2, respectively.

In corresponding applications, the outer crucible material of the outercrucible 30-1 can be, e.g., a metal or a metal alloy, in particular,e.g., tungsten or a tungsten alloy.

In other applications, an outer crucible material of the outer crucible30-1, e.g., can be more advantageous, which is selected as a ceramicmaterial, for example on the basis of Al₂O₃ or Y₂O₃.

In the case of a measuring arrangement according to the invention, thefeatures and embodiment details of the individual components describedabove with reference to FIGS. 1 to 10 can be arbitrarily combined withone another, insofar as the respective features or embodiments,respectively, are compatible with one another.

The aspect of a centering of the crucible 10, which has already beendiscussed in the examples according to FIGS. 1 to 10, only requires thelateral positioning of the crucible 10 on the sensor 20. To increase thereproducibility of the measurements performed in the context of thethermal analysis, it would also be advantageous, when the crucible 10could always be arranged in a predetermined rotational position withrespect to the sensor 20 in a simple manner for such measurements. Inparticular in the case of crucibles, which are embodied at leastapproximately rotationally symmetrically in known measuringarrangements, it can be assumed in practice that the crucibles arearranged by the user in any or random rotational positions,respectively, with respect to the sensor.

To eliminate this problem, a measuring arrangement, in particular, e.g.,a measuring arrangement of the type as already described here withregard to FIGS. 1 to 10, can be embodied according to the presentinvention with an anti-rotation protection for the crucible, in order toprovide a predetermined rotational position of the crucible with respectto the sensor 20 when the crucible 10 is arranged on the sensor 20.

Exemplary embodiments of such an anti-rotation protection according tothe invention are described with reference to FIGS. 11 and 12.

FIG. 11 shows, in schematic top view, an essentially circular outercontour of a crucible 10, which is arranged on a sensor 20 (illustratedin a dashed manner).

In this exemplary embodiment, a predetermined rotational position of thecrucible 10 with respect to the sensor 20 is ensured by means of apositive engagement of a protrusion 21 with a depression 19, wherein theprotrusion 21 in FIG. 11 is arranged on the sensor 20 (or a furthercomponent of the respective measurement arrangement arranged in astationary manner to the sensor 20), and the depression 19 is arrangeddirectly on the outer side of a jacket of the crucible 10.

As an alternative to the shown arrangement of the depression 19 directlyon the outer side of the crucible jacket, it can also be considered aspart of the invention to arrange the depression 19 at a differentlocation in the area of the outer side of the crucible 10, for example,on an outer side of a component surrounding the crucible 10, such as,e.g., of an “outer crucible” of the type, as has already been describedabove.

Under the assumption that the crucible 10 is not separated from acorresponding outer crucible between different measurements in thecontext of one or a plurality of thermal analyses, an anti-rotationprotection provided directly only for the outer crucible is thensynonymous with an anti-rotation protection for the crucible 10.

As an alternative to an outer crucible as attachment location for adepression, which ensures the anti-rotation protection, it couldfurthermore be considered to arrange such a depression on a component,which is provided specifically for this purpose and which surrounds therespective crucible 10 in a sleeve-like manner.

With regard to the arrangement of the protrusion 21 on the sensor 20 (oron a further components, which is arranged in a stationary manner to thesensor 20), it can in particular be provided as part of the inventionthat the protrusion 21 is arranged directly on the inner side (innercircumference) of the sensor edge, when a “sensor edge” of the type, ashas already been described, which protrudes upwards, on the top side ofthe sensor 20 is present.

FIG. 12 shows an exemplary embodiment of a crucible 10 on a sensor 20,again, e.g., in a measuring arrangement according to one of FIGS. 1 to10, wherein a modification as compared to the example of FIG. 11 quasilies only in that the arrangement locations of the protrusion and of thedepression are interchanged. In the case of the example of FIG. 12, aprotrusion 19′ is thus arranged in the area of the outer side of thecrucible 10, and a depression 21′ is arranged on the sensor 20 (or acomponent, which is arranged in a stationary manner thereto), betweenwhich the positive engagement ensures the predetermined rotationalposition of the crucible 10 with respect to the sensor 20.

All of the designs (in particular concrete arrangement locations)described with regard to the depression 19 and the protrusion 21 of FIG.11, can analogously be used for the design or arrangement, respectively,of the protrusion 19′ or of the depression 21′, respectively, in theexample of FIG. 12.

In the case of the examples of FIGS. 11 and 12, the depression (19 or21′, respectively) and the correspondingly configured protrusion (21 or19′, respectively), have an elongated cross sectional surface, viewed ina plane orthogonally to the direction of the engagement. In this case,the depression can thus in particular form a groove, which runs in astraight line, with which a rib engages, which is dimensioned to fit andwhich runs in a straight line.

A straight course of the above-mentioned elongated cross sectionalsurface of the depression (19 or 21′, respectively) and, correspondingthereto, of the protrusion (21 or 19′, respectively), is preferablyoriented in the vertical direction of the measuring arrangement.

It is further preferred, as can also be seen in the examples of FIGS. 11and 12, when the depression (19 or 21′, respectively), and,corresponding thereto, the protrusion (21 or 19′, respectively) have arounded depression bottom or a rounded protrusion end, respectively. Inthe alternative or in addition, it can be provided, e.g., that a crosssection of the depression and, corresponding thereto, a cross section ofthe protrusion, decrease, viewed in the engagement direction (as can beseen in the examples of FIGS. 11 and 12).

Deviating from the example according to FIGS. 11 and 12, the depression19 or 21′, respectively, and, corresponding thereto, the protrusion 21or 19′, respectively, could in each case also have a non-elongated crosssectional surface, e.g., an at least approximately circular crosssectional surface. For this purpose, the depression and the protrusioncould in particular each be configured in an at least approximatelyfrustoconical or approximately hemispherical manner.

In the alternative or in addition to the design described in the exampleaccording to FIG. 11 and FIG. 12, with a positive engagement of aprotrusion with a depression, the predetermined rotational position ofthe crucible 10 with respect to the sensor 20 could also be realized inthat the crucible 10 has a “marking” (which is visible for a user) inthe area of its outer side, in order to make it possible for the user toarrange the crucible 10 on the sensor 20 in the predetermined rotationalposition of the crucible 10 by means of the marking.

Such a marking can in particular be embodied, e.g., as a markingprotrusion or as a marking depression. The crucibles 10 shown in FIGS.11 and 12 would also be suitably embodied in this respect for such asimplified embodiment of an anti-rotation protection. In the case ofthese crucibles 10, the depression 19 or the protrusion 19′,respectively (also without presence of a corresponding protrusion 21 ora depression 21′, respectively), can represent such visible markings.

The designs of the anti-rotation protection described above with regardto FIGS. 11 and 12 can be used in the case of each of the exemplaryembodiments of measuring arrangements, which have already been describedfurther above (FIGS. 1 to 10).

1. A measuring arrangement for a thermal analysis of a sample, having: acrucible for storing a sample, a sensor for measuring a temperature ofthe sample when the crucible is arranged on the sensor, characterized byan anti-rotation protection for the crucible, in order to provide apredetermined rotational position of the crucible with respect to thesensor when the crucible is arranged on the sensor.
 2. The measuringarrangement according to claim 1, wherein the crucible has a marking,which is visible for a user, in the area of its outer side, in order tomake it possible for the user to arrange the crucible on the sensor inthe predetermined rotational position of the crucible with respect tothe sensor by means of the marking.
 3. The measuring arrangementaccording to claim 2, wherein the marking is embodied as a markingprotrusion or as a marking depression, wherein the marking protrusion orthe marking depression, respectively, preferably has a configuration,which is elongated in the vertical direction of the crucible and/or awidth in the range of between 0.1 mm and 1.0 mm, viewed in acircumferential direction of the crucible.
 4. The measuring arrangementaccording to claim 1, wherein, when the crucible is arranged on thesensor, the predetermined rotational position of the crucible withrespect to the sensor is ensured by means of a positive engagement of aprotrusion with a depression, wherein the protrusion is arranged on thesensor or on a further component of the measuring arrangement, which isarranged in a stationary manner to the sensor, and the depression isarranged in the area of the outer side of the crucible, or vice versa.5. The measuring arrangement according to claim 4, wherein thedepression arranged in the area of the outer side of the crucible or theprotrusion arranged in the area of the outer side of the crucible,respectively, are arranged directly on the outer side of a jacket of thecrucible.
 6. The measuring arrangement according to claim 4, furtherhaving a component, which surrounds the crucible at least in the area ofa jacket of the crucible, in particular an outer crucible storing thecrucible, wherein the depression arranged in the area of the outer sideof the crucible or the protrusion arranged in the area of the outer sideof the crucible, respectively, is arranged on the outer side of thiscomponent surrounding the crucible in particular outer crucible.
 7. Themeasuring arrangement according to claim 4, wherein the depressionand/or the protrusion has a round cross sectional surface, viewed in aplane orthogonally to the direction of the engagement.
 8. The measuringarrangement according to claim 4, wherein the depression and/or theprotrusion has an elongated cross sectional surface, viewed in a planeorthogonally to the direction of the engagement.
 9. The measuringarrangement according to claim 4, wherein a top side of the sensor has asensor edge protruding upwards, and wherein the protrusion is arrangedon the sensor or the depression is arranged on the sensor, respectively,in the area of this sensor edge.
 10. A method for the thermal analysisof a sample, comprising: temperature-controlling a sample arranged in asample chamber according to a temperature program, in the course ofwhich a chamber temperature in the interior of the sample chamber ischanged, measuring a sample temperature of the sample in the course ofthe temperature program, providing a measuring arrangement having: acrucible for storing a sample; a sensor for measuring a temperature ofthe sample when the crucible is arranged on the sensor, characterized byan anti-rotation protection for the crucible, in order to provide apredetermined rotational position of the crucible with respect to thesensor when the crucible is arranged on the sensor.
 11. The methodaccording to claim 10, wherein the chamber temperature has a maximumvalue of at least 500° C. in the course of the temperature program. 12.The measuring arrangement according to claim 2, wherein, when thecrucible is arranged on the sensor, the predetermined rotationalposition of the crucible with respect to the sensor is ensured by meansof a positive engagement of a protrusion with a depression, wherein theprotrusion is arranged on the sensor or on a further component of themeasuring arrangement, which is arranged in a stationary manner to thesensor, and the depression is arranged in the area of the outer side ofthe crucible, or vice versa.
 13. The measuring arrangement according toclaim 5, wherein the depression and/or the protrusion has a round crosssectional surface, viewed in a plane orthogonally to the direction ofthe engagement.
 14. The measuring arrangement according to claim 5,wherein the depression and/or the protrusion has an elongated crosssectional surface, viewed in a plane orthogonally to the direction ofthe engagement.
 15. The measuring arrangement according to claim 5,wherein a top side of the sensor has a sensor edge protruding upwards,and wherein the protrusion is arranged on the sensor or the depressionis arranged on the sensor, respectively, in the area of this sensoredge.